This invention relates to a method and apparatus for tracking the inventory and history of specific individual rubber products.
There is a need to track the history of rubber objects which are durable and have a long but finite useful life. Tires, for example, and for the purpose of illustration more specifically aircraft tires, may be retreaded many times, and there is a need to keep track of the number of times such a tire is retreaded, in addition to the number of landings and take-offs which such tires are subjected to. Letter and number markings placed on the tires can be washed off, scuffed off, or covered with other substances that make them unreadable. The use of bar code labels to replace markings has been attempted, but have been found to be only slightly more useful than letter and number markings.
Hind, in U.S. Pat. No. 4,625,101, has designed a bar code that is cut into the sidewall rubber of a tire wherein each bar of the code has an angle that reflects light in a specific manner. Since these carved bar codes are read by scanning with a light source, and their readability is dependent on the reflectance of light, they have some of the same drawbacks as other kinds of markings and, in addition, are labor intensive to produce.
It is an object of the invention to provide a system to provide and read an identification code and/or part number on a rubber object wherein the reading of the code is not dependent on a light source or the reflectance of light from the rubber object. Further objects of the invention will be apparent from the following description and claims.